Furnace refractory supporting structure

ABSTRACT

AN IMPROVED METALLURGICAL FURNACE CONSTRUCTION UTILIZING SPECIALLY DESIGNED METAL PLATES INTERPOSED BETWEEN THE FURNACE REFRACTOR BRIKES TO SECURE THEM TO THE STRUCTURAL STEELWORK OF THE FURNACE. EACH OF THE PLATES IS SECURED AT ONE END TO THE FURNACE STEELWORK AND AT THE OTHER END HAS FLANGES WHICH EXTEND TRANSVERSELY FROM OPPOSITE FACES OF THE PLATE. THE FLANGES EXTENDING FROM ONE FACE OF THE PLATE ARE SPACED A GREATER DISTANCE FROM   THE INNER END OF THE PLATE THAN THE FLANGES EXTENDING FROM THE OPPOSITE FACE OF THE PLATE. EACH OF THE BRICKS SUSPENDED FROM SUCH PLATES HAS A SLOT EXTNEDING ACROSS TWO OPPOSITE FACES OF THE BRICK, NEAR ITS INNER END. THE SLOT IN ONE FACE IS SPACED A GREATER DISTANCE FROM THE INNER END OF THE BRICK THAN THE SLOT IN THE OPPOSITE BRICK FACE.

E. B. MILLER, SR

FURNACE REFRACTORY SUPPORTING STRUCTURE Nov. 16, 1971 2 Sheets-Sheet 1 Filed June 23. 1970 I I m 1 W m .J 1 W M G 6 5 l a .1 B 3 n 2 M W E k? 1 1% hn \n wl 33 LI Nov. 16, 1971 Filed June 23, 1970 E. B. MILLER, SR

FURNACE REFRACTORY SUPPORTING STRUCTURE 2 Sheets-Shani: 2

INVENTOR Eda/in B. Millers:

United States Patent O 3,620,178 FURNACE REFRACTORY SUPPORTING STRUCTURE Edwin B. Miller, Sr., Baltimore, Md., assignor to Bethlehem Steel Corporation Filed June 23, 1970, Ser. No. 49,088 Int. Cl. F23n1 5/02 US. Cl. 110-99 B 14 Claims ABSTRACT OF THE DISCLOSURE An improved metallurgical furnace construction utilizing specially designed metal plates interposed between the furnace refractory bricks to secure them to the structural steelwork of the furnace. Each of the plates is 15 secured at one end to the furnace steelwork and at the other end has flanges which extend transversely from opposite faces of the plate. The flanges extending from one face of the plate are spaced a greater distance from the inner end of the plate than the flanges extending from 0 the opposite face of the plate. Each of the bricks suspended from such plates has a slot extending across two opposite faces of the brick, near its inner end. The slot in one face is spaced a greater distance from the inner end of the brick than the slot in the opposite brick face.

BACKGROUND OF THE INVENTION This invention relates to an improved furnace refractory construction and mounting structure and more particularly to an improved refractory construction for those portions of metallurgical furnaces subjected to relatively high temperatures.

In metallurgical furnaces exposed to high temperatures, as for example open hearth furnaces, portions of the refractory brickwork are suspended from the furnace structural framework. This is the case in roof, nose, and apron portions of open hearth furnaces. The usual manner of construction in these areas is to suspend the refractory bricks from cast metal hangers which are secured to the furnace steelwork. Generally, such hangers have an inverted T-shaped lower end, with the cross bar or prongs extending symmetrically from opposite sides of the lower end of the hanger stem. Special bricks, which are adapted to engage such hangers, have transverse slots in their opposite faces and these slots are spaced aquidistant from the ends of the bricks. The brick slots engage the prongs or '/2 portion of the bottom cross bars of the hangers. Provision is also made in the bricks to accommodate the stem portions of such hangers. This is accomplished by providing, in conjunction with each transverse slot, another slot extending longitudinally from the transverse slot to the inner end of the brick. An example of this form of construction is shown in US. Pat. No. 2,738,744 to L. S. Longenecker, and is best shown in FIGS. 2 and 3 of that patent.

There are several disadvantages to the aforementioned type of construction. The cast hangers are relatively expensive. The symmetry of the T-shaped lower end of the hangers and inner ends of the bricks, with their slots lying in the same plane, constitutes an inherent weakness in the construction. In areas where such construction is used, there is a tendency for the bricks to fail and break off through the plane of reduced cross sectional area which extends between the slots. When the refractory bricks wear back to the slots the supporting hangers are directly eyposed to the heat of the furnace and soon fail. When a hanger or hangers fail, the bricks which the hangers had been holding fall from place and leave an opening for the furnace heat and gases to pass through and attack the remainder of the supporting hangers and the furnace framework. Obviously, the portion of the brick between the hanger slots and the inner end of the brick is seldom fully utilized, with the result that the refractory life in areas of the furnace using this type of construction could be improved.

SUMMARY OF THE INVENTION Therefore it is an object of the present invention to provide a furnace refractory construction and mounting structure which overcomes the aforementioned problems of the prior art.

It is another object of the invention to provide a refractory construction which utilizes the full thickness of the refractory bricks of a furnace.

It is another object of the invention to provide a suspension plate which is designed to support refractory bricks in a furnace more efficiently than does prior art suspension means.

It is a further object of the invention to provide an improved furnace construction which makes use of specially designed bricks and suspension plates that result in a more economical construction than that of the prior art.

The objects of this invention are achieved by providing a furnace construction which makes use of specially designed plates and bricks in a manner to permit full utilization of the brick thickness prior to the time the furnace is taken out of service to replace the brickwork. Each of the plates has provisions at one end to secure it to the structural steel framework of the furnace. At the opposite end of each plate are flanges which extend transversely from opposite faces of} the plate. The flanges extending from one plate face are spaced a greater distance from the inner end of the plate than the flanges extending from the opposite plate face. Each of the bricks which cooperates with the plates has a slot extending across two opposite faces of the brick, near its inner end. The slot in one face is spaced a greater distance from the inner end of the brick than the slot in the opposite brick face so that both slots do not lie in the same transverse plane of the brick.

BRIEF DESCRIPTION OF THE DRAWINGS Referring to the drawings:

FIG. 1 is a cross-section through the nose portion of a metallurgical furnace which has been constructed in accordance with this invention.

FIG. 2 is an elevation view of the flanged plate of this invention.

FIG. 3 is a top view of the flanged plate of FIG. 2.

FIG. 4 is an end view of the flanged plate of FIG. 2.

FIG. 5 is an isometric view of the flanged plate brick construction of this invention with a different embodiment of plate design.

FIG. 6 is an isometric view of a slotted refractory brick used in conjunction with the construction of this invention.

FIG. 7 is a side view of a portion of the brick of FIG. 6.

FIG. '8 is an isometric view of an arrangement of a furnace which illustrates the furnace framework, flanged plate, and slotted refractory bricks of the construction of this invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 there is shown the uptake portion of an open hearth furnace 10 which includes a sloping chill wall 11, having a nose portion 12, flat chill wall 13, and slag pocket chill wall 14. Sloping chill wall 11, as hereinafter more fully described, is suspended from strong rigid members such as H beams or hanger castings that are connected by means of brackets 16 to furnace structural steel framework 17. Slag pocket chill wall 14, as hereinafter more fully described, is secured to furnace structural steel framework 17. Sloping chill wall 11 and slag pocket chill wall 14 are constructed in accordance with this invention.

Referring to FIG. 1, sloping chill wall 11 includes a plurality of rows, for example a, b, c, d, and e, of bricks 18 which are suspended from plate hangers 19 that are arranged in rows, for example a, b, c, d, e, and f, that are interposed between the rows of bricks 18.

Referring to FIGS. 2, 3, and 4, plate hanger 19' of length i and thickness j has inner end 20 and outer end 21. Along inner end 20 are slots 22 which are adapted to engage flanges of hanger casting 15. Spaced from inner end 20 and adjacent outer end 21 of plate hanger 19 are flanges 23 and 24 which extend from opposite faces 25 and 26 respectively, of the plate hanger 19. Flanges Z3 and 24 each having a width k and length l are spaced apart a distance In. Flanges 23 are spaced from plate inner end 20 a distance 11, which is greater than the distance p that flanges 24 are spaced from the plate inner end. Plate hangers 19 are suspended from hanger casting 15 with their flanges 23 all extending in the same direction, as indicated by the arrow in FIG. 1. Naturally, flanges 24 of plate hangers 19 will extend in the opposite direction.

Referring to FIGS. 6 and 7, brick 18 has inner end 27 and outer or exposed end 28, edges 29 and 30 and faces 31 and 32. Extending transversely of face 31 a distance s from inner end 27 is slot 33 and extending transversely of face 32 a distance I from inner end 27 is slot 34. Slot 33 is spaced a greater distance from inner end 27 than slot 34, i.e. distance s is greater than distance t, so that slots 33 and 34 are spaced apart a distance u which is equal to the distance in between flanges 23 and 24 of plate hanger 19. The inner portions 31 and 32' of brick faces 31 and 32 respectively, are each set back or recessed a distance v which is approximately equal to /2 the thickness 1' of hanger plate 19 so that bricks 18 will be in face to face contact when suspended from hanger plates 19. Slots 33 and 34 in brick faces 31 and 32 respectively, each have a depth w which is slightly greater than the width k of flanges 23 and 24 of plate hanger 19, to facilitate assembly.

Referring to FIG. 1, plate hangers 19 are suspended from the hanger castings 15 with their flanges 23 all extending in the same direction, as indicated by the arrow. Naturally, flanges 24 on the opposite face of each of plate hangers 19 will all face in the opposite direction. In like manner, slots 33 of bricks 18 will all face in one direction so as to engage outer flanges 23 of plate hangers 19, and slots 34 of the bricks will all face in the opposite direction so as to engage inner flanges 24 of the plate hangers. In brick rows a, b, c, d and e, slots 34 in bricks 18 of brick row a will engage flanges 24 of plate hangers 19 of plate hanger row a and slots 33 in bricks 18 of brick row a will engage flanges 23 of plate hangers 19 of plate hanger row b; slots 34 in bricks 18 of row b will engage flanges 24 of plate hangers 19 of plate hanger row b and slots 33 in bricks 18 of brick row I; will engage flanges 23 of plate hangers 19 of plate hanger row 0', etc.

Referring to FIG. 8, vertical slag pocket chill wall 14 is constructed in a manner similar to that described above. Plate hangers 19 are connected to structural steel framework by means of slots 22' which engage the flanges of the steel framework 17 so that the flanges 23 and 24' lie in a vertical plane. Bricks 18 are identical in design to bricks 18 described above and extend horizontally and outwardly from plate hangers 19' with slots 33' and 34' of the bricks engaged by flanges 23' and 24' respectively, of hangers 19'.

In FIG, 5 is shown another embodiment of the plate hanger of the construction of this invention. In this embodiment each plate hanger 19" has a single flange 23" extending transversely from the other face of the plate hanger. Each of these flanges extends for approximately the full length of the hanger. Naturally in this construction flanges 23 and 24" are separate pieces of metal which are secured to the main body of plate hanger 19" in any convenient manner, as for example by welding.

The above described construction of this invention has many advantages over prior art furnace construction, which make use of cast hangers having symetrical lower ends and bricks adapted to be engaged by smuch cast hangers. The plate hanger of this invention can be easily fabricated or punched-out of light weight structural plates, for example 12 ga. sheet metal, at a lower cost than that of a cast metal hanger or hangers that will hold an equal number of bricks. At furnace operating temperatures the sheet metal hanger plates will oxidize and expand to establish a firm contact between adjacent bricks and so interlock the bricks that fragments of spalled or badly worn bricks will be prevented from falling out of position. In addition, by spacing notch 33 in brick 18 a greater distance than notch 34 from brick inner end 27, there is much less tendency for the brick to spall through the diagonal plane between these notches than there would be if the notches were in the same transverse plane of the brick.

I claim:

1. In a furnace comprising a steel framework and refractory bricks, the improvement comprising:

(A) support means connected to said steel framework;

(B) first and second rows of plate means connected to said support means, each said plate means having 1) first and second faces,

(2) an inner end and an outer end,

(3) first flange means extending transversely from said plate means first face and spaced from said plate means inner end,

(4) second flange means extending transversely from said plate means second face and spaced from said plate means inner end a lesser distance than said first flange means is spaced from said inner end, and

(C) a row of bricks extending between said first and second rows of plate means and outwardly therefrom, a plurality of bricks in said row of bricks each having (1 first and second faces,

(2) an inner end and an outer end,

(3) first slot means in said second brick face spaced from said inner end of said brick and adapted to engage said first flange means of said second row of plate means,

( 4) second slot means on said first brick face spaced a lesser distance than said first slot means from said inner end of said brick and adapted to engage said second flange means of said first row of plate means.

2. Plate means as recited in claim 1 wherein said first flange means is perpendicular to said first face of the plate means.

3. Plate means as recited in claim 2 wherein said first flange means is a rectangular projection perpendicular to said first face of the plate means.

4. Plate means as recited in claim 3 wherein said first flange means is a plurality of equidistant rectangular projections perpendicular to said first face of the plate means.

5. Plate means as recited in claim 4 wherein said second flange means is perpendicular to said second face of the plate means.

6. Plate means as recited in claim 5 wherein said second flange means is a rectangular projection perpendicular to said second face of the plate means.

7. Plate means as recited in claim 6 wherein said second flange means is a plurality of equidistant rectangular projections perpendicular to said second face of the plate means.

8. Plate means as recited in claim 7 further comprising means to engage said plate means with said steel framework.

9. Plate means as recited in claim 8 wherein said engagement means comprises a plurality of cutouts in said plate mean inner end and extending from said first face to said second face.

10. Bricks as recited in claim 9 wherein the depth of said first slot means in said second brick face is greater than the perpendicular projection of said first flange means.

11. Bricks as recited in claim 10 wherein the depth of said second slot means in said first brick face is greater than the perpendicular projection of said second flange means.

12. Bricks as recited in claim 11 wherein said first and second faces contain a transverse recess extending from said inner end toward said outer end.

References Cited UNITED STATES PATENTS 1,500,240 7/ 1924 Griffith 110-99 A 2,606,017 8/ 1952 Longenecker 110-99 X 3,148,641 9/1964 Longenecker 11099 A 3,400,672 9/ 1968 Dickson 11099 KENNETH W. SPRAGUE, Primary Examiner 

